package com.auto.learning.tools;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;

import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.drawable.BitmapDrawable;
import android.os.Build;
import android.renderscript.Allocation;
import android.renderscript.Element;
import android.renderscript.RenderScript;
import android.renderscript.ScriptIntrinsicBlur;
import android.util.Log;
import android.view.View;

/**
 * 高斯模糊
 * 
 */
public class FastBlur {

	public static Bitmap doBlur(Bitmap sentBitmap, int radius,
			boolean canReuseInBitmap) {

		Bitmap bitmap;
		if (canReuseInBitmap) {
			bitmap = sentBitmap;
		} else {
			bitmap = sentBitmap.copy(sentBitmap.getConfig(), true);
		}

		if (radius < 1) {
			return (null);
		}

		int w = bitmap.getWidth();
		int h = bitmap.getHeight();

		int[] pix = new int[w * h];
		bitmap.getPixels(pix, 0, w, 0, 0, w, h);

		int wm = w - 1;
		int hm = h - 1;
		int wh = w * h;
		int div = radius + radius + 1;

		int r[] = new int[wh];
		int g[] = new int[wh];
		int b[] = new int[wh];
		int rsum, gsum, bsum, x, y, i, p, yp, yi, yw;
		int vmin[] = new int[Math.max(w, h)];

		int divsum = (div + 1) >> 1;
		divsum *= divsum;
		int dv[] = new int[256 * divsum];
		for (i = 0; i < 256 * divsum; i++) {
			dv[i] = (i / divsum);
		}

		yw = yi = 0;

		int[][] stack = new int[div][3];
		int stackpointer;
		int stackstart;
		int[] sir;
		int rbs;
		int r1 = radius + 1;
		int routsum, goutsum, boutsum;
		int rinsum, ginsum, binsum;

		for (y = 0; y < h; y++) {
			rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;
			for (i = -radius; i <= radius; i++) {
				p = pix[yi + Math.min(wm, Math.max(i, 0))];
				sir = stack[i + radius];
				sir[0] = (p & 0xff0000) >> 16;
				sir[1] = (p & 0x00ff00) >> 8;
				sir[2] = (p & 0x0000ff);
				rbs = r1 - Math.abs(i);
				rsum += sir[0] * rbs;
				gsum += sir[1] * rbs;
				bsum += sir[2] * rbs;
				if (i > 0) {
					rinsum += sir[0];
					ginsum += sir[1];
					binsum += sir[2];
				} else {
					routsum += sir[0];
					goutsum += sir[1];
					boutsum += sir[2];
				}
			}
			stackpointer = radius;

			for (x = 0; x < w; x++) {

				r[yi] = dv[rsum];
				g[yi] = dv[gsum];
				b[yi] = dv[bsum];

				rsum -= routsum;
				gsum -= goutsum;
				bsum -= boutsum;

				stackstart = stackpointer - radius + div;
				sir = stack[stackstart % div];

				routsum -= sir[0];
				goutsum -= sir[1];
				boutsum -= sir[2];

				if (y == 0) {
					vmin[x] = Math.min(x + radius + 1, wm);
				}
				p = pix[yw + vmin[x]];

				sir[0] = (p & 0xff0000) >> 16;
				sir[1] = (p & 0x00ff00) >> 8;
				sir[2] = (p & 0x0000ff);

				rinsum += sir[0];
				ginsum += sir[1];
				binsum += sir[2];

				rsum += rinsum;
				gsum += ginsum;
				bsum += binsum;

				stackpointer = (stackpointer + 1) % div;
				sir = stack[(stackpointer) % div];

				routsum += sir[0];
				goutsum += sir[1];
				boutsum += sir[2];

				rinsum -= sir[0];
				ginsum -= sir[1];
				binsum -= sir[2];

				yi++;
			}
			yw += w;
		}
		for (x = 0; x < w; x++) {
			rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;
			yp = -radius * w;
			for (i = -radius; i <= radius; i++) {
				yi = Math.max(0, yp) + x;

				sir = stack[i + radius];

				sir[0] = r[yi];
				sir[1] = g[yi];
				sir[2] = b[yi];

				rbs = r1 - Math.abs(i);

				rsum += r[yi] * rbs;
				gsum += g[yi] * rbs;
				bsum += b[yi] * rbs;

				if (i > 0) {
					rinsum += sir[0];
					ginsum += sir[1];
					binsum += sir[2];
				} else {
					routsum += sir[0];
					goutsum += sir[1];
					boutsum += sir[2];
				}

				if (i < hm) {
					yp += w;
				}
			}
			yi = x;
			stackpointer = radius;
			for (y = 0; y < h; y++) {
				// Preserve alpha channel: ( 0xff000000 & pix[yi] )
				pix[yi] = (0xff000000 & pix[yi]) | (dv[rsum] << 16)
						| (dv[gsum] << 8) | dv[bsum];

				rsum -= routsum;
				gsum -= goutsum;
				bsum -= boutsum;

				stackstart = stackpointer - radius + div;
				sir = stack[stackstart % div];

				routsum -= sir[0];
				goutsum -= sir[1];
				boutsum -= sir[2];

				if (x == 0) {
					vmin[y] = Math.min(y + r1, hm) * w;
				}
				p = x + vmin[y];

				sir[0] = r[p];
				sir[1] = g[p];
				sir[2] = b[p];

				rinsum += sir[0];
				ginsum += sir[1];
				binsum += sir[2];

				rsum += rinsum;
				gsum += ginsum;
				bsum += binsum;

				stackpointer = (stackpointer + 1) % div;
				sir = stack[stackpointer];

				routsum += sir[0];
				goutsum += sir[1];
				boutsum += sir[2];

				rinsum -= sir[0];
				ginsum -= sir[1];
				binsum -= sir[2];

				yi += w;
			}
		}

		bitmap.setPixels(pix, 0, w, 0, 0, w, h);

		return (bitmap);
	}
	
	/** 
     * 打印高斯模糊处理时间，如果时间大约16ms，用户就能感到到卡顿，时间越长卡顿越明显，如果对模糊完图片要求不高，可是将scaleFactor设置大一些。 
     */ 
	@SuppressWarnings("deprecation")
	@SuppressLint("NewApi")
	public static void blur(Bitmap bkg, View view,Context context) {
		try {
//		    float scaleFactor = 15;//图片缩放比例；  
//		    float radius = 20;//模糊程度  
		    
		    float scaleFactor = 8;//图片缩放比例；  
		    float radius = 10;//模糊程度  
		  
		    /*ByteArrayOutputStream baos = new ByteArrayOutputStream();
		    bkg.compress(Bitmap.CompressFormat.PNG, 50, baos);
		    InputStream isBm = new ByteArrayInputStream(baos.toByteArray());
		    Bitmap overlay = BitmapFactory.decodeStream(isBm);*/
		    
//		    Log.d("blur", view.getMeasuredWidth() + "--" + view.getMeasuredHeight());
		    Bitmap overlay = Bitmap.createBitmap((int) (view.getMeasuredWidth() / scaleFactor), (int) (view.getMeasuredHeight() / scaleFactor), Bitmap.Config.ARGB_4444);  
		    Canvas canvas = new Canvas(overlay);  
		    canvas.translate(-view.getLeft() / scaleFactor, -view.getTop()/ scaleFactor);  
		    canvas.scale(1 / scaleFactor, 1 / scaleFactor);  
		    Paint paint = new Paint();  
		    paint.setFlags(Paint.FILTER_BITMAP_FLAG);  
		    canvas.drawBitmap(bkg, 0, 0, paint);  
		  
		    overlay = FastBlur.doBlur(overlay, (int) radius, true);  
		    if (Build.VERSION.SDK_INT  >= 16) {
		    	view.setBackground(new BitmapDrawable(context.getResources(), overlay));  
			}else {
				view.setBackgroundDrawable(new BitmapDrawable(context.getResources(), overlay));
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	} 
	
	@SuppressLint("NewApi")
	public static Bitmap blur2(Bitmap bkg, View view,Context context) {  
	    long startMs = System.currentTimeMillis();  
	    float scaleFactor = 20;//图片缩放比例；  
	    float radius = 20;//模糊程度  
	  
	    Bitmap overlay = Bitmap.createBitmap((int) (view.getMeasuredWidth() / scaleFactor), (int) (view.getMeasuredHeight() / scaleFactor), Bitmap.Config.ARGB_4444);  
	    Canvas canvas = new Canvas(overlay);  
	    canvas.translate(-view.getLeft() / scaleFactor, -view.getTop()/ scaleFactor);  
	    canvas.scale(1 / scaleFactor, 1 / scaleFactor);  
	    Paint paint = new Paint();  
	    paint.setFlags(Paint.FILTER_BITMAP_FLAG);  
	    canvas.drawBitmap(bkg, 0, 0, paint);  
	  
	    overlay = FastBlur.doBlur(overlay, (int) radius, true);  
	      
	    /** 
	     * 打印高斯模糊处理时间，如果时间大约16ms，用户就能感到到卡顿，时间越长卡顿越明显，如果对模糊完图片要求不高，可是将scaleFactor设置大一些。 
	     */  
	    Log.i("jerome", "blur time:" + (System.currentTimeMillis() - startMs));  
	    return overlay;
	}
	
	
	/**
	 * 设置高斯模糊
	 * 
	 * @param bkg
	 * @param view
	 */
	@SuppressLint("NewApi")
	public static void blurByRenderScript(Bitmap bkg, View view,Context context) {
		float scaleFactor = 20;
		float radius = 10; 
		Bitmap overlay = Bitmap.createBitmap(
				(int) (view.getMeasuredWidth() / scaleFactor),
				(int) (view.getMeasuredHeight() / scaleFactor),
				Bitmap.Config.ARGB_4444);
		Canvas canvas = new Canvas(overlay);
		canvas.translate(-view.getLeft() / scaleFactor, -view.getTop()
				/ scaleFactor);
		canvas.scale(1 / scaleFactor, 1 / scaleFactor);
		Paint paint = new Paint();
		paint.setFlags(Paint.FILTER_BITMAP_FLAG);
		canvas.drawBitmap(bkg, 0, 0, paint);
		RenderScript rs = RenderScript.create(context);
		Allocation overlayAlloc = Allocation.createFromBitmap(rs, overlay);
		ScriptIntrinsicBlur blur = ScriptIntrinsicBlur.create(rs, overlayAlloc.getElement());
		blur.setInput(overlayAlloc);
		blur.setRadius(radius);
		blur.forEach(overlayAlloc);
		overlayAlloc.copyTo(overlay);
		view.setBackground(new BitmapDrawable(context.getResources(), overlay));
		rs.destroy();
	}
	
	
	@SuppressLint("NewApi")
	public static void blurBitmap(Bitmap bitmap, View view,Context context){  
        Bitmap outBitmap = Bitmap.createBitmap(bitmap.getWidth()/5, bitmap.getHeight()/5, Config.ARGB_8888);  
        RenderScript rs = RenderScript.create(context);  
        ScriptIntrinsicBlur blurScript = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));  
        Allocation allIn = Allocation.createFromBitmap(rs, bitmap);  
        Allocation allOut = Allocation.createFromBitmap(rs, outBitmap);  
        blurScript.setRadius(8);  
        blurScript.setInput(allIn);  
        blurScript.forEach(allOut);  
        allOut.copyTo(outBitmap);  
        bitmap.recycle();  
        rs.destroy();  
        view.setBackground(new BitmapDrawable(context.getResources(), outBitmap));
    }
}